hugo

Drip U73b. freq response on one channel
« on: May 09, 2020, 10:33:49 AM »
Hi,
i finished a drip U73b. I noticed a difference between left and right channels.
On the left one, i have a big loss of low freq, i mean more than normal.
On the right one i have some loss on low but its normal regarding the original use of this compressor.
I do not know how to find where the issue comes from...if somebody can help me.
Regards,
H


Sc

Re: Drip U73b. freq response on one channel
« Reply #1 on: May 17, 2020, 03:29:08 AM »
Hi Hugo
This could be about everywhere - I guess you checked all parts beeing in the correct place, controlled transformer connections and you swapped tubes from one channel to the other. Then you might check the DC-Voltages in Lim - position and compare to the original schematics. In case you have a scope, you might follow the AC signal from input to output and find at least the stage, where it occurs. Be careful not to test at points, where a lot of DC is present (unless your scope handles the offset). Always after the coupling caps. You can do the same by amplifying the signal from these points, but make sure, that you block the DC over a decent coupling cap. Probably it's not the sidechain, but not for shure.
Regards Walter

hugo

Re: Drip U73b. freq response on one channel
« Reply #2 on: May 17, 2020, 01:03:19 PM »
Hi Hugo
This could be about everywhere - I guess you checked all parts beeing in the correct place, controlled transformer connections and you swapped tubes from one channel to the other. Then you might check the DC-Voltages in Lim - position and compare to the original schematics. In case you have a scope, you might follow the AC signal from input to output and find at least the stage, where it occurs. Be careful not to test at points, where a lot of DC is present (unless your scope handles the offset). Always after the coupling caps. You can do the same by amplifying the signal from these points, but make sure, that you block the DC over a decent coupling cap. Probably it's not the sidechain, but not for shure.
Regards Walter
thank you for your support


 

Related Topics

  Subject / Started by Replies Last post
2 Replies
2085 Views
Last post July 29, 2009, 04:32:09 AM
by hotbaby
1 Replies
786 Views
Last post March 03, 2019, 07:11:44 PM
by hugo
22 Replies
3265 Views
Last post May 20, 2020, 01:15:26 PM
by hugo
22 Replies
1404 Views
Last post May 01, 2020, 03:37:11 AM
by Sc